The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A number of coupling techniques have been developed to efficiently couple power between optical fibers and optical devices, especially between a semiconductor laser and an optical fiber, in optical communications and industrial laser systems. For example, proper alignment allows an increase in the coupling efficiency and, thus, a decrease in the coupling loss between the laser and the fiber or receiver, permit an increase in fiber output. However, efficient coupling of semiconductor lasers to optical fibers has been a problem of general concern since the advent of optical fiber laser transmission. Generally, as a result of coupling inefficiencies, a percentage of the laser output is not utilized. Thus, the laser has to be run at a correspondingly higher current to yield the same-coupled power into fiber that a more efficient coupling scheme could provide. In addition, operation of the laser at higher currents results in greater heat to be dissipated and raises questions of long term stability and reliability of the laser itself. As laser-cutting heads can need repair or replacement, realignment of the laser head to the transmission optical fiber with the optical lenses in the laser head is necessary. Typically, power meters are coupled to a laser head optics that attempt to allow maximization of the output of the system caused by proper laser to fiber input coupling. Because of the nature of industrial lasers, power measurement in a working environment may not be the best measure of fiber alignment.